1. Field of the Invention
This invention relates generally to a V-block internal combustion type engine lubrication circuit and specifically, to an improved V-block engine lubrication circuit device for a V-block, cam in block, General Motors type engine.
2. Description of Related Art
Lubrication of cam bearings and main or crankshaft bearings in a conventional 90 degree V-block, cam in block, General Motors engine is well known in the art. Lubrication is accomplished by oil being supplied to the cam bearings from the oil pump via an oil supply passage on the right side of the engine. Some of the oil from the right side oil passage is directed, by intersecting oil passages, to the crankshaft, or main bearings to provide for their lubrication. In addition, the oil passage on the right side provides lubrication for the lifters on the right side of the engine.
Along with the oil passage on the right side of the engine, the oil pump simultaneously supplies oil to an oil supply passage on the left side of the engine. The left side passage supplies oil for the lifters on the left side of the engine. The oil pump also supplies oil to the first cam bearing and the first crankshaft bearing which are physically located closest to the oil pump.
With the exception of the first bearings, the right side oil passage provides oil for all cam bearings, crankshaft bearings and right side lifters. The right side oil passage has a continuous flow of oil through the passage. The continuous flow of oil on the right side removes heat from that side of the engine.
The left side passage has very little flow because it is plugged at the end farthest from the oil pump and only supplied oil to the left side lifters. The lifters do not require as much oil as the bearings and, with the exception of seeping necessary for lifter lubrication, the oil in the left side passage lies stagnant. Without continuous flow, the oil on the left side of the engine becomes hotter than the oil on the right side of the engine. This results in a heat imbalance in the engine, with the left side running hotter than the right side. The heat imbalance causes uneven wear and premature failure of the bearings and other moving parts of the engine.
Other engine problems are caused by the lubrication of the cam and crankshaft bearings being supplied solely from the right side oil passage. For example, a car with an automatic transmission at normal highway speeds or moderate road speed the converter locks up and puts pressure on the thrust bearing. The transmission then goes into overdrive which reduces the engine RPM which in turn reduces oil flow and oil pressure. With insufficient oil at this critical stage, the thrust bearing wears.
The front end of the right side oil passage terminates in a plug that infringes the passage enough to aide in high speed oil starvation experienced by components supplied by the right side oil passage.
Having a single oil passage supply the cam and crankshaft bearings also results in a drop in oil pressure at idle speeds. The bearings are not supplied with sufficient lubrication at idle speed and results in increased friction causing premature bearing wear. This is most critical when returning to idle from highway driving as when paying a toll. Oil at this stage is at its least viscosity and engine component wear is at its greatest because the engine is at its hottest temperature.
Contributing to these problems is the fact that two crankshaft bearings supply oil to multiple return oil passages whereas the other two crankshaft bearings supply oil to one oil return passage. This results in two of the four crankshaft bearings requiring more oil than the other two. When all the crankshaft bearings are supplied by the right side oil passage two of the four bearings do not receive sufficient oil under all operating conditions.